Giovanni Battista Venturi

Giovanni Battista Venturi was born in Bibbiano, Italy, in 1746, and entered the Catholic priesthood in 1769 — the standard route for a quick-minded young man of his generation into the intellectual life of Italy. He taught at the University of Modena for three decades, held several diplomatic posts under the Napoleonic government of northern Italy, and spent his spare time in physics, chemistry, and the history of science.

His 1797 paper 'Recherches expérimentales sur le principe de la communication latérale du mouvement dans les fluides' laid out what is now called the Venturi effect. Venturi showed experimentally that when fluid flows through a pipe whose cross-section narrows and then widens again, the velocity rises in the narrow section and the static pressure drops there — a direct consequence of mass conservation and Bernoulli's principle working in tandem. He recommended the constricted tube as a flow meter, a usage that became standard in hydraulic engineering throughout the nineteenth century and is still taught in fluid mechanics courses today.

Venturi was also one of the first historians of Leonardo da Vinci's scientific notebooks, transcribing and publishing substantial portions of them in 1797 — a century before the notebooks were fully catalogued. His scientific reputation rests narrower than his interests, but the narrowed pipe and the drop in pressure have proven durable enough to keep his name on every fluids syllabus.